VRay Physical Camera DOF vs. Zdepth/Nuke (just curious about your thoughts)

[patrick_ortman]

So, 99% of the time we just poop out a zdepth pass and do DOF in Nuke. But today, since I have the time and curiousity, I rendered a client shot two ways. First, the usual Zdepth pass. So fast. So adjustable in post! Second, using DOF in Maya VRay Physical camera. Yeah, of course had to keyframe the focus distance. And the renderfarm charged about 20% more for the render. And it's totally not adjustable in post/Nuke. But... wow, it looks so much better. Way better bokeh, no weird edge artifacts (the ones not supposed to be there), all that. It just looks and feels so much better than doing it in post. Like a real camera would do. So, anyone have any thoughts on this? I am wondering if we did the render in Deep, maybe that would give us something close to the VRay Physical Camera, with just a ZDepth pass.

[beenyweenies]

This won’t answer your question regarding deep EXRs, but I personally bailed on doing DoF in post like a decade ago. The additional render cost and inflexibility is a price I’m willing to pay in trade for realistic, perfect DoF. I have never seen any plug-in or comping solution that can hold its own when compared side by side. And even those solutions that don’t result in terrible artifacts like you mentioned DO fail to compensate for the realistic calculations that light and color undergo in a true DoF solution. The additional render time required has dropped significantly in the last decade as well. I've found that good render settings can make up for some of that.

Now, having said all of that - I do not have experience with deep rendering and it’s possible that doing this solves most of the artifact issues like odd fringing, especially with shallower depth of field, since the pixel data should be there to calculate what is behind every object. I doubt deep rendering would contribute anything to the other issue of light calculations not looking the same as a native DoF render, maybe someone else can weigh in on that.

[seq]

We also do DOF at render level since over 10 years. The quality is superb and worth every Euro or rather kilowatt-hour of our render farm. We build up a camera rig which feeds the focus distance. Rendered DOF is really a big plus for every CGI work.